Listed below are some possible responses to typical climate statements and questions that may pop up.
You don’t believe in global warming?
Yes, I do. The Earth has warmed by roughly 0.8 degrees Celsius since the late 1800s.
You don’t believe in climate change?
Yes, I do. The Earth’s climate has changed multiple times, just in the past 1,000 years.
CO2 levels are rising and the Earth is warming.
CO2 concentrations have risen slightly over the past century or so, to 0.04% of the earth’s atmosphere. At the same time, though, solar output has increased tremendously. This significant increase in solar activity—the mostin as much as 2,000 years—is likely to be the key driver of 20th century warming.
But CO2 levels are the highest in 800,000 years.
CO2 levels in the atmosphere are currently among the lowest ever recorded on the planet. The past 800,000 years is a convenient timeframe, however, since the earth has undergone repeated glacial cycles in that time—which has progressively lowered atmospheric CO2.
CO2 is a greenhouse gas. More CO2 means more warming.
CO2 possesses a major limitation as a greenhouse gas. As demonstrated in laboratory studies, CO2 exponentially loses heat-trapping capacity as its concentration increases. This happens because, even in small quantities, CO2 quickly becomes opaque to a certain spectrum of infrared radiation. It rapidly absorbs all of the infrared radiation it can, which means that adding additional quantities of CO2 will not contribute any meaningful warming. CO2 is also a “well-mixed gas,” which means that its concentrations are distributed throughout the atmosphere. Consequently, its heat-trapping function is essentially saturated throughout the troposphere and stratosphere.
But higher CO2 levels mean higher temperatures? I saw that graph in ‘An Inconvenient Truth’.
Al Gore left out a key point when citing the parallel relationship between historical levels of CO2 and temperature. Carbon dioxide dissolves in water, and cold water can hold more CO2 than warm water. When the climate cools, the oceans gradually cool, slowly drawing in more CO2 and lowering atmospheric CO2 content. When the climate warms, as seen at the start of the most recent interglacial period roughly 18,000 years ago, the oceans gradually release CO2. (This is the reason why a bottle of soda kept in hot sunlight will leak or burst— because the warmer soda water is no longer able to hold all of the dissolved CO2.) When global temperatures change, CO2 concentrations follow along.
Scientists say that CO2 is warming the Earth.
Yes, CO2 is a greenhouse gas, and it helps maintain warmth in the atmosphere. But as noted above, CO2’s heat-trapping function is essentially saturated by the current level of 0.04 percent. Furthermore, climate models actually project that most of the presumed “man-made” warming will come from an increase in atmospheric water vapor. The principal idea of “anthropogenic global warming” is that the small amount of additional warming contributed by CO2 (before it becomes saturated) will cause more water vapor to enter the atmosphere. Since water vapor is the primary greenhouse gas of the atmosphere (and is responsible for roughly80 percent of the “greenhouse effect”), this water vapor will create positive feedback for further warming.
Unfortunately, the theory disregards the cooling feedback caused by clouds (since atmospheric water vapor transitions to clouds). Cloud cover provides net cooling by reflecting solar radiation back into space, shading ground surfaces, and producing rain (precipitation not only cools surface temperatures but also scrubs atmospheric CO2).
But 97% of scientists believe in global warming?
What’s most amusing is that, truthfully, no one really knows how many scientists there are in the world. Or what they actually think of global warming. Or how many of them are scientists in relevant scientific disciplines. However, the “97% consensus” figure is actually a methodologically flawed statement. Only 32.6% of the papers studied in the infamous John Cook study actually stated a position endorsing anthropogenic (man-made) global warming. However, 97% of those said that “recent warming is mostly man-made.” And so what we have is a misleading statement that has become cited as fact.
Well, 2015 was the hottest year ever, and now 2016 is even hotter. Explain that?
The warming experienced in 2015-2016 is a direct result of the current El Niño.
El Niño is caused by global warming
El Niño is a naturally occurring phenomenon. It happens when prevailing winds start to fade after progressively “piling up” water in the western Pacific Ocean. This surplus, warmer water washes back over the eastern Pacific, releasing tremendous amounts of heat. 2015’s spike in temperatures was due to El Niño. It would be dishonest and inaccurate to claim that 2015’s increase in surface temperatures was simply due to man-made warming. Here’s more on the latest El Niño, and why even alarmists admit that it is not a manifestation of man-made warming.
The “pause in global temperatures” is just people denying that the Earth is getting hotter and hotter
Satellite measurements from both UAH-Huntsville and RSS clearly show the “pause” in global temperatures (I.e. a net flatlining of temperatures over the past 15-20 years.) The current El Niño is already fading, and one can reasonably expect to see a drop-off in temperatures. Since 1950 with 11 of the last 15 strong El Niño eventsflipped to a La Niña. More significantly, the pause has been the subject of numerous debates and research papers. Climate alarmists don’t deny that it has happened, they just offer various explanations. Even a February 2016 paper co-authored by Michael Mann shows that there was indeed a global warming pause.
There is no “pause” in global warming
There is real concern as to the accuracy and reliability of recent temperature measurements being reported by NOAA. Last year, NOAA adjusted temperatures downward in the last century to make the last 15 years appear warmer. Magically, they “erased” the pause. By including measurements of seawater temperatures taken from the engine manifolds of ocean-going vessels, they essentially cooled the past to warm the present. Here’s anacademic summary of papers that quickly debunked NOAA’s “new” temperature findings. It’s interesting to note that it is NOAA’s revised measurements that are being used to make claims such as “warmest year ever” etc…
With the pause removed, NASA then quietly adopted NOAA’s “cooked” temperature record so that both agencies could make these “warmest ever” claims. Currently, NOAA is under House investigation for tampering with temperature data and colluding with activists to promote the Obama administration’s global warming agenda.
NOTE: These are simple points, based on elementary climate and geologic science. It would be helpful if more people studied the basic issues involved in the climate debate before accepting the alarmist rhetoric trumpeted by a media that thrives on sensationalism.